<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
		<link rel="stylesheet" type="text/css" href="../css/bootstrap.css"/>
	</head>
	<body>
		<div class="row">
			<div class="col-xs-6 col-sm-3">.col-xs-6 .col-sm-3</div>
			<div class="col-xs-6 col-sm-3">.col-xs-6 .col-sm-3</div>

			<!-- Add the extra clearfix for only the required viewport -->
			<div class="clearfix visible-xs-block"></div>

			<div class="col-xs-6 col-sm-3">.col-xs-6 .col-sm-3</div>
			<div class="col-xs-6 col-sm-3">.col-xs-6 .col-sm-3</div>
		</div>
		  
		<!-- jQuery (Bootstrap 的所有 JavaScript 插件都依赖 jQuery，所以必须放在前边) -->
		<script src="../js/jquery-3.5.1.js"></script>
		<!-- 加载 Bootstrap 的所有 JavaScript 插件。你也可以根据需要只加载单个插件。 -->
		<script src="../js/bootstrap.min.js"></script>
		
	</body>
</html>
